1. Unit 6 – Lesson 4
Ionic Equations

2. Dissolution
process by which an ionic solid breaks into ions as it dissolves in a polar liquid, such as water

3. NaCl(s)  Na+(aq) + Cl-(aq)
We can write these solutions as ions if they dissolve (aqueous)
NaCl(s)  Na+(aq) + Cl-(aq)

4. Ag+(aq) + Cl-(aq)  AgCl(s)
Precipitation
process by which ions leave a solution and form a precipitate
(insoluble in water)
Ag+(aq) + Cl-(aq)  AgCl(s)

5. AgNO3(aq) + NaCl(aq)  AgCl(s) + NaNO3(aq)
Show all the aqueous ionic compounds as the separate ions they really are.
AgNO3(aq) NaCl(aq)  AgCl(s) NaNO3(aq)
Ag+(aq)
+ NO3-(aq)
+ Na+(aq)
+ Cl-(aq)
 AgCl(s)
+ Na+(aq)
+ NO3-(aq)
AKA total or complete ionic equations

6. Writing Ionic Equations
Step 1 – Balance the equation
Cu(NO3)2(aq) NaOH(aq)  Cu(OH)2(s) NaNO3(aq)
Cu(NO3)2(aq) + 2NaOH(aq)  Cu(OH)2(s) + 2NaNO3(aq)
If there is more than one of an ion, you must write it as a coefficient in the ionic equation
Step 2 – Write all aqueous compounds as ions
+ 2NO3-(aq)
Cu2+(aq)
+ 2Na+(aq)
+ 2OH-(aq) 
Cu(OH)2(s) +
2Na+(aq) +
2NO3-(aq)

7. Spectator Ions
Ions which do not participate directly in a reaction in solution, they just “watch”, therefore they remain unchanged
Cu2+(aq) + 2NO3-(aq) + 2Na+(aq) + 2OH-(aq) 
Cu(OH)2(s) + 2Na+(aq) + 2NO3-(aq)

8. Which ions are just watching the show?
Na+ and NO3-

9. Writing Net Ionic Equations
Includes only those components of the solution that undergo a change (spectator ions are removed)
Writing Net Ionic Equations
Step 1 – Begin with Ionic Equation
Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq)  AgCl(s) + Na+(aq) + NO3-(aq)
Step 2 – Cross out spectator ions
Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq)  AgCl(s) + Na+(aq) + NO3-(aq)
Ag+(aq) + Cl-(aq)  AgCl(s)
= Net Ionic Equation

10. 1. Mg(s) + NiSO4(aq)  Ni(s) + MgSO4(aq) (single replacement)
Write the complete and net ionic equations for the following equations.
1. Mg(s) + NiSO4(aq)  Ni(s) + MgSO4(aq) (single replacement)
Complete: Mg(s) + Ni2+(aq) + SO42-(aq)  Ni(s) + Mg2+(aq) + SO42-(aq)
Net: Mg(s) + Ni2+(aq)  Ni(s) + Mg2+(aq)
2. MgCl2(aq) + 2AgNO3(aq)  2AgCl(s) + Mg(NO3)2(aq) (double replacement)
Complete: Mg2+(aq) + 2Cl- (aq) + 2Ag+ + 2NO3-(aq)  2AgCl(s) +
Mg2+(aq) + 2NO3-(aq)
Net: 2Cl- (aq) + 2Ag+(aq)  2AgCl(s)